Let’s break down the process into easy-to-follow steps.

Make the Cupcakes:

1. Preheat and Prepare: Preheat the oven to 350ºF (175°C). Line a cupcake tin with liners.
2. Combine Dry Ingredients: In a small bowl, whisk together the flour, baking powder, and salt. Zest the lemons and set the zest aside.
3. Cream Butter and Sugar: In the bowl of your electric mixer, beat the butter until creamy. Add in the sugar and beat on medium speed, scraping down the sides if needed, and increasing it to high speed for 2 to 3 minutes, until the sugar and butter is fluffy.
4. Add Eggs and Extracts: Beat in each egg and white until incorporated, then add the vanilla and lemon extract (if using) and lemon zest until combined.
5. Alternate Dry and Wet Ingredients: Beating on low speed, add in half of the dry ingredients until combined, then add in the milk and lemon juice. Add in the remaining dry ingredients and beat until combined. Do not overmix.
6. Fill Cupcake Liners: Using an ice cream scoop or 1/4 cup measure, scoop the batter into the liners, filling them 3/4 of the way full.
7. Bake: Bake for 16–18 minutes, or until the tops are set and a toothpick inserted into the center comes out clean.
8. Cool: Let cool completely in the tin, then transfer to a wire rack.

Make the Lavender Frosting:

1. Cream Butter: Add butter to the bowl of your electric mixer fitted with the paddle attachment and beat until creamy.
2. Gradually Add Powdered Sugar and Lavender: With the mixer on low speed, gradually add the powdered sugar and finely chopped lavender.
3. Increase Speed and Beat: Increase the speed of the mixer, scraping down the sides if needed, beating the frosting until fluffy and combined.
4. Add Vanilla: Beat in the vanilla extract.
5. Adjust Consistency (if needed): If the frosting seems too thick, beat in the tablespoon of milk (or cream). If it seems too runny or too thin, you can beat in more powdered sugar, ¼ cup at a time.
6. Add Food Coloring (optional): Once the frosting is a spreadable consistency, drop in the purple food coloring (if using) and mix until evenly colored.

Assemble:

1. Frost Cupcakes: Frost the cooled cupcakes.
2. Garnish (optional): Top with a few fresh lavender flowers if you wish.

These steps are easy to follow.